Surgically implanted flexible bag-type mammary prostheses have suffered a serious problem with the bag rupturing in certain cases after surgical implantation. This is believed to occur more frequently when the bag develops a crease; however, several theories have been advanced to explain just why such a bag ruptures. Some believe it is due to the stress differential between inner and outer surfaces of a bag wall section and a crease area caused by one wall surface being in compression and the other being in tension. Others believe that this is caused by a change in the physical properties such as modulus, etc., over a prolonged period of maintaining a crease. Still others believe that the bag failures to be caused at least in part by friction between opposing wall sections in a fold area. This latter view is explained in Rees et al. in "The Use of Inflatable Breast Implants," Plastic and Reconstructive surgery, Volume 52, Number 6, December 1973, pp. 609-615. It has been known for many years that in some surgical implantations of a flexible shell or bag containing an inflatable liquid, such as normal saline, rupture occurs at a crease area, perhaps many months or years after surgical implantation. This type of bag wall failure is known as "fold flaw." Many theories as to the mechanism of such failure have been proposed, but heretofore there has been no solution to such recognized problem.
In a copending application Ser. No. 350,916 filed Feb. 22, 1982 many of the possible contributing factors for the rupture of these prostheses are described, pointing out that the self-abrasion injury to the bag wall was the dominant mechanism. That patent application discloses a method of reducing the rupture of the prosthesis by injecting an inflating liquid, such as normal saline, containing a uniform dispersion of lubricious polymer particles in such liquid. These particles act as a lubricant between two inner surface areas that periodically slide against each other in a crease area of the prosthesis bag.